Your company has set up a Classic Load Balancer with EC2 Instances behind them. These EC2 Instances are spun up via an Autoscaling group. In your company, there is normally a spike in traffic in the beginning and end of the day. The ELB and Autoscaling Groups have been created with the default settings. Sometimes, it has been noticed that there are timeouts or partially rendered pages when the instances terminate. How can this be resolved?

Answer options:

A.Change the maximum number of Instances setting in the Autoscaling Group.
B.Change the Connection Draining timeout in the ELB.C.Disable Connection Draining.
D.Add another Autoscaling group to the ELB.

Answer – B
The most likely reason is that when the instances are terminated by Autoscaling, the requests are partially fulfilled and not completed. In such a case, you can increase the connection draining on the ELB.Option A is invalid because it is when the Instances are terminating that is the issue.
Option C is invalid because you can disable connection draining if you want your load balancer to immediately close connections to the instances that are de-registering or have become unhealthy. When connection draining is disabled, any in-flight requests made to de-registering or unhealthy instances are not completed.
Option D is invalid because you don’t need multiple Autoscaling groups for this.
For more information on Connection Draining, please refer to the below URL
https://docs.aws.amazon.com/elasticloadbalancing/latest/classic/config-conn-drain.html